On satellite telecommunication systems using a constellation of satellites moving in orbits of HEO (High Earth Orbit) or MEO (Medium Earth Orbit) or LEO (Low Earth Orbit) type, and fixed or mobile ground stations forming terminals of the satellite access system, the use of at least two antennas is required to allow a handover of the communication link ensuring the service supplied to the ground station from an origin first descending satellite at end of line of sight to a destination second ascending satellite at the start of line of sight, when the antennas of the ground stations are directional.
Hitherto, the multi-antenna ground stations, whether manufactured or which have been proposed, comprise two antennas and use just one of them throughout the period separating two consecutive handovers. Moreover, during the implementation of a handover, these ground stations require a dual demodulation chain.
Recently, ground stations have been developed which make it possible to couple, between two link handovers, the reception of a same carrier from a same satellite targeted by the two antennas, and to thus produce a reception diversity on the two antennas.
The patent application EP 2 779 482 A1 describes the architecture of such a ground station with two antennas which make it possible to process in diversity only the signal received from two antennas originating from a same satellite.
The architecture described in the abovementioned document, and the architectures of the ground stations produced and in service to date, do not make it possible to produce a seamless link handover between two satellites during which a reception diversity on at least two antennas targeted on the two satellites can be used to reinforce the quality and the reliability of the handover. Nor do these architectures allow for an uninterrupted use of a multi-antenna reception diversity during a link handover between two origin and destination reception diversity configurations of antennas pointing exclusively to the first satellite for the origin configuration and to the second satellite for the destination configuration. Nor do these architectures have the modularity required that allows an addition as and when necessary of a new antenna to improve the reception performance levels.
A first technical problem is to propose a ground station architecture having at least two mobile direction antennas which improves the seam lessness of a link handover between a first satellite and a second satellite.
A second technical problem is to propose a ground station architecture that makes it possible to perform, during the reception link handover, a reception diversity on at least two antennas, one pointing to the first satellite and another pointing to the second satellite.
A third technical problem is to propose a ground station architecture which allows for an uninterrupted use of a multi-antenna reception diversity during a link handover between two origin and destination reception diversity configurations of antennas pointing exclusively to the first satellite for the origin configuration and pointing exclusively to the second satellite for the destination configuration.
A fourth technical problem is to propose a modular architecture which allows for an addition as and when required of a new antenna to improve the reception performance levels.
A fifth technical problem is to propose a multi-antenna ground station architecture, solving at least one of the first, second, third and fourth technical problems, which makes it possible, when there is a plurality of at least two antennas pointing to a same satellite, to send to said satellite a plurality of carriers carrying a communication signal that are identical, said carriers being adapted in transmission to supply, in reception from the satellite, a wave front of the carriers that is aggregated coherently.